Boiler water-back.



W. F. SELLERS.

BOILER WATER BACK. APPLICATION man JUNE 18, 1912.

1,148,543. Patented Aug. 3, 1915.

2 SHEETS SHEET l.

INVENTOR WITNESSES 1 v ATTORNEY :QLUMBIA PLANOLIRAPH Cu WASHINGTON, n.c.

W. F. SELLERS.

BOILER WATER BACK. APPLICATION FILED JUNE 18.1912.

Patented Aug. 3, 1915.

2 SHEETS-SHEET 2.

ATTORNEY WITNESSES 55m r I COLUMBIA PLANOGBAPH COuWASHINGTON, D. c.

pnrrnn srarns PATENT onnien VVILLIAJVI F. SELLERS, OF EDGEMOOR,DELAWARE, ASSIGNOR TO EDGE M003. IRON COlvIPANY, OF EDGEMOOR, DELAWARE,A CORPORATION OF DELAWARE.

BOILER WATER-BACK.

Specification of Letters Patent.

Patented Aug. 3, 1915.

To all whom it may concern Be it known that 1, WILLIAM F. SELLERS, acitizen of the United States, residing in Edgemoor, Brandywine Hundred,county of New Castle, and State of Delaware, have invented a certain newand useful Improvement in Boiler WV-atenBacks, of which the following isa true and exact description, reference being had to the accompanyingdrawings, which form a part thereof.

y present invention relates to boilers such as are employed in thegeneration of steam for power purposes, and particularly to theconstruction and arrangement of the water back with its pipe connectionsto the boiler prop er which it is frequently found desirable to employin connection with the furnace chamber of such a boiler.

The primary object of my invention is to provide a simple and efi'ectiveboiler construction in which the water back extends into the boilerhousing from one side of the latter, and has the necessary twocirculating pipe connections to the boiler proper, each leading from theone outer externally exposed end of the water back, and in which thewater back and its pipe connections are so constructed and arranged thatthe water back may be taken apart for cleaning or re pairs in a simpleand expeditious manner, and without destruction of, or injury to anyportion of the boiler housing.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, and of the advantages possessed by it, reference should be hadto the accompanying drawings and descriptive matter in which I haveillustrated and described various forms of apparatus embodying myinvention. v

Of the drawings, Figure l is a sectional elevation of a water tubeboiler equipped with my new invention, Fig. 2 is an end elevation of theexternally exposed end of the water back, Fig. 3 is a partial sectionalelevation of the boiler, the section being taken on a planecorresponding to the line 33 of Fig. 2, Fig. 4 is a section of the waterback taken on the line 4.i of Fig. 3, and Fig. 5 is a longitudinalsection of a portion of a modified form of Water back. y In Fig. l ofthe drawings, I have illus trated the use of my improved water back ina. water tube boiler of well known type. It

is to be understood, however, that the improved water back is capable ofeffective utilization in many different types of boilers. As shown inFig. 1, the boiler proper comprises inclined water tubes A connected attheir opposite ends to an upper front header B and a lower rear headerC. The two headers are also connected above the water tubes by the steamand water drum D. The boiler is inclosed in a housing E of the usualtype, and F represents transverse masonry, bridge or battle wallpertaining to the furnace chamber. G represents the grate which, in theparticular type of boiler construction illustrated, is in the form of anendless belt. My improved water back, in the form shown, comprises ahorizontal tube H which extends into the boiler housing from one side ofthe latter and lies between the horizontal portion of the baflle wall Fand the end of the grate G, and has for its primary function to preventhot coals on the traveling grate from being carried by the latter intothe position in which they may fall off the rear end of the grate. Thewater back tube H projects through one side wall E of the boilerhousing, and has its outer exposed end provided with a flange H. Theinner end of the tube H, which is closed as indicated at H? extends intoand is supported by the wall E at the opposite side of the boiler fromthe wall E. The flange H at the expos d outer end of the tube H isdetachably connected to the flange J of a fitting J. The latter isformed with a chamber J communicating with and forming an ex tension ofthe interior passage of the tube H. From the chamber J leads a lateralport or passage J and the fitting is provided with a flange J adapted tobe detachably connected to the flange at the end of the pipe K whichconnects the port J to the front header B of theboiler adjacent theupper end of that header. The fitting J is also provided at its outerend with a chamber J which, as shown, is coaxial with, but of largerdiameter than the chamber J and the chambers J and J are connected by apassage J S which, as shown, is slightly smaller in diameter than thebore of the tube H. A port J leads from the chamber J of the fitting J,and the fitting is provided with a flange J 7 adapted to be detachwaterthrough ably secured to the flanged end of the pipe L, which connectsthe port J to the rear header 0 of the boiler adjacent to the bottom ofthe header. As shown,

is formed with a flange J against, which may be detachably secured acover plate J which normally closes the outer end of the chamber JWithin the tube His placed a tube I, the outer end of which is connectedto the fitting J in such manner as to prevent direct communicationbetween the chambers J and J At its inner end the tube I is open andterminates short of the closed end H of the pipe H so that water passingfrom the rear header C of the pipe L and the port J 6 to the chamber J 5of the fitting J, may pass from the latter through the channel formed bythe tube I to the inner end of the waterback, and from thence may flowback to the chamber J 2 of the fitting J, through the channel formed bythe annular space between the outer wall of the tube I into the innerwall of the tube II. From the chamber J the water may pass to the frontheader B of the boiler through the port J 3 and the pipe K.

In the particular form of apparatus shown, the connection between theouter end of the tube I and the fitting J comprises a collar I securedto the outer end of the tube I and having a body portion fitting snuglyin the passage J and a flange which abuts against the inner end wall ofthe chamber J Projections J formed on the inner side of the cover plateJ normally bears against the outer end of the tube I and prevents itsaxial displacement. It will be understood that there is no necessitywhatever for making an absolutely tight joint between the outer end ofthe tube I and the fitting J. The difference between the pressures inthe chambers J 2 and J 5 is slight, and any slight leakage which mayoccur from one of the chambers into the other through the joint betweenthe flanged end of the tube I and the fitting J would have noappreciable effect on' the efiiciency of the apparatus.

To prevent the inner tube I from sagging, spacing provisions may be madewhereby the tube I is supported from the tube H at one or more pointsalong its length. These spacers may advantageously be formed as shown ofpieces of band metal M bent snugly about the pipe I and having ends 'Mbent away from the tube to form feet bearing against the inner wall ofthe tube H.

With the arrangement described, it will be apparent that an effectivecirculation of the water back is obtained by the gravity flow of therelatively cool water from the lower end of the'rear header C throughthe pipe L to the water back, the water, after being heated in the waterback, passing from the latter through the pipe the fitting J boilerthrough the K to the upper portion of the front header B. i

It will be apparent to those skilled in the art that the water back maybe readily taken apart for cleaning or repairs without disturbing thewalls of the boiler housing in any way. This taking apart of the waterback may be effected without any disturbance of the pipe, connections bysimply removing the cover plate J the tube I. It will be understood thatthe provisions employed for. spacing the tube I centrally with respectto the tube H should be of such a character as not to interfere with thewithdrawal of thepipe I. In the form shown in the drawings, the spacingmembers M are of such a size relative to the passage way J that theyreadily pass through the latter when the tube ,I is slightly displacedlaterally position in which it is coaxial with the tube A. The tube Imay be so laterally displaced of course as soon as the enlarged flangedend I passes out of the fitting J.

Instead of'taking the water back apart by removing the cover plate J andwithdrawing the tube I through the outer end of the fitting, the fittingJ may be uncoupled from the pipe H and the pipes J and K, and thefitting J and the tube I can then be moved bodily away from the tube H.A very important advantage of my improved water back arrangement arisesfrom the fact that it is common practice to arrange batteries of boilersin pairs in which case, as indicated in Fig. 3, the housing wall E iscommon to and serves as a central dividing wall between the furnacechambers of the two boilers. Heretofore in such boilers, water backconsisting of a tube extending transversely through the furnace chamberof each boiler and connected at one end to the boiler proper by a pipeembedded in the wall E This arrangement is open to the serious objectionthat the pipe connection embedded in the central wall of the boilerhousing is exposed 'to undesirably high temperatures and deterioratesrapidly, and, moreover, this pipe cannot be gotten at or removed forcleaning or repairs without the practical destruction in whole or inpart of the central wall. lVith my'arrange ment, the water back and itspipe connections between the water back and the boiler proper are notexposed to the high temperatures of the interior of the boiler housing.

Where the space between the outer surface of theside'wall E of theboiler housing and an adjacent boiler housing or other immovableapparatus or an adjacent wall of the boiler roomisrestricted, it maysometimes be desirable to form the tube I in de tachable sections a i asshown in Fig. 5. These sections may be detachably connected andwithdrawing from its normal it has'been the practice to employ a wtogether as by means of the threaded collars N. It will be understoodthat there is no more necessity for making perfectly tight jointsbetween the adjacent ends of adjacent sections 2' than there is formaking a perfectly tight joint between the outer end of the tube I andthe fitting J.

lVith the arrangement described, the cross sectional area of the annularspace between the tubes I and H may well be made equal to, or even lessthan the cross sectional area of the pipes L and K with the advantageousresult that the flow velocity of the water through the annularinter-tube space will be made equal to or even higher than the velocityof the water through the tubes L and K. Those skilled in the art willunderstand that the rapidity of flow of the water through the hottestportions of the apparatus thus obtained and the film-like character ofthe stream in which it flows, increase the rapidity with which heat isabstracted from the tube H as is desirable in order to keep down thetemperature of the latter. The relatively rapid flow of water throughthe water back and particularly through the hottest portion thereof isadvantageous also in that it tends to reduce the deposit of impuritiesin the water back thus prolonging the intervals permissible betweensuccessive cleaning operations and adding to the safety of theapparatus.

Another important characteristic of my water back construction andarrangement is the provision of a free return passage to the boiler fromthe water back for the steam forming in the water back as well as forthe water passing through the water back, and the avoidance of allpockets in the water back in which steam may collect.

It will be apparent that with the water back construction disclosed, thetubes H and I are free to expand and contract as they vary intemperature independently of each other, and without subjecting anyportion of the water back to undesirable strains. Those skilled in theart will understand that the fitting J may readily be cast from a singleadjusting pattern with the passages J and J at any angle desired, thusgreatly facilitating the use of my improved water back in boilers ofdifferent types and shapes. v lVhile in accordance with the provisionsof the statutes I have illustrated and described the best forms of myinvention now known to me, it will be apparent to those skilled in theart that changes may be made in the form of the apparatus disclosed;without departing from the spirit of my invention, and that certainfeatures of the invention may sometimes be employed with advantagewithout a corresponding use of other features of the invention.

Having now described my invention what I claim as new and desire tosecure by Letters Patent is, I

1. The combination with a boiler proper, its housing and furnacechamber, of a water back projecting into and removable from the furnacechamber through an outer wall f the boiler housing and formed with twochannels communicating at the inner end of the water back, and pipesdetachably connected to the outer end of the Water back externally ofthe boiler housing and connecting one of said channels to the boilerproper at one point and the other channel to the boiler proper atanother point.

2. The combination with a boiler proper, its housing and furnacechamber, of a water back projecting into and removable from the furnacechamber'through an outer Wall of the boiler housing, and comprising pairof tubes arranged one within the other with a space between the outerwall of the inner tube and the inner wall of the outer tube whichconnects at its inner end with the interior of the inner tube, and meansdetachably connected to the water back externally of the boiler housingand to the boiler providing a water supply passage leading to theinterior of said inner tube from the boiler, and providing a free returnpassage from the inter-tube space for water and steam said returnpassage opening to the boiler at a level above that at which said supplypassage opens to the boiler.

3. The combination with a boiler proper, its housing and furnacechamber, of a water back projecting into and removable from the furnacechamber through an outer wall of said housing and comprising a pair oftubes separated from each other by an inter tube space communicatingwith the interior of the inner tube at the inner end of the water back,a fitting to which the outer ends of the two tubes are connected andformed with one chamber surrounding the inner tube and communicatingwith the inter-tube space and with a second chamber communicating withthe interior of the inner tube, and conduits detachably secured to saidfitting and connecting the two chambers to different portions of theboiler proper.

4. The combination with a boiler proper, its housing and furnacechamber, of a water back projecting into the furnace chamber through anouter wall of said housing and comprising a pair of tubes separated fromeach other by an inter-tube space communicating with the interior of theinner tube at the inner end of the water back, a fitting forming a meansends of the two tubes are detachably connected and formed with twopassages communicating one with the inter-tube space and the other withthe interior of the inner tube, and conduit connections leading from bywhich the outer the two passages to diiierent portions of the boilerproper, said inner tube being divided into separable longitudinalsections.

5. The combination with a boiler proper, its housing and furnacechamber, of a water back projecting into and removable from the furnacechamber through an outer wall of said housing and-comprising a pair oftubes separated from'each other by an intertube space communicat ng wlththe interior of the inner tube at the inner end of the water back, afitting to which the outer ends of the two tubes are connected andformed with two passages communicating one with the inter-tube spaceand'the other with the interior of the inner tube, means interposedbetween the two tubes and spacing them apart, and conduits detachablysecured to said fittings and connecting the two passages to differentportions of the boiler proper.

6. A water back adapted to project into the interior of a boiler throughthe boiler housing and comprising a pair of tubes arranged one withinthe other and separated from each other by an inter-tube spacecommunicating with the interior of the inner tubeat the inner end of thewater back, and a fitting to which the outer ends of the two tubes areconnected, said fitting being Copies of this patent may be obtained forformed with one chamber surrounding the inner tube, and communicatingwith inner-tube space and with a second chamber communicating with theinterior of the inner tube, and having provisions for detachablyconnecting to said fitting two pipes, one communicating with one, and

, the other with the second of said chambers.

7 A water back adapted to project into the interior of a boiler throughthe boiler housing, and comprising a pair of tubes arranged one withinthe other and separated from each other by an inter-tube spacecommunicating with the interior of the inner tube at the inner end ofthe water back, a hollow fitting, means for detachably connecting theouter end of said outer tube to said fitting, means for securing theouter end of said'inner tube into said fitting so that said inner tubedivides the interior of said fitting into two chambers communicating onewith said inner tube and the other with said inter-tube space, and meansfor detachably connecting two pipes to said fitting, one communicatingwith one, and the other with the second of said chambers.

WM. F. SELLERS.

Witnesses ARNOLD KA'rz, D. STEWART.

five cents each, by addressing the Commissioner of Patents,

Washington, D. C.

the

